To me, its quite simple,,,,my caller can hear me OK but because of my hearing problems I cant hear them very well.So, what is needed is a device, into which I place my phone and via a amplified speaker,I hear at a louder volume.

To reply with my caller I simply take up the phone and speak to them.

I had thought that if I put a microphone to the phones loudspeaker and connected it to my cd player That would give me an amplified conversation,that I could actualy hear.

But,there must be many people with a similar problem,so I have trolled the internet but not found anything.

Anyone have any suggestions? Who knows an inventot?

Firstly.. What phone do you possess?

Depending on your model of mobile phone and it's feature set, you could

Get a WIRED HEADSET (mic and speaker)

Get an Amplified WIRED HEADSET (mic and speaker)

Get a special Bluetooth Wireless Headset or Earpiece (mic and speaker)

Get a Bluetooth hands-free speakerphone (mic, speaker with feedback prevention circuit)

Another option is Bluetooth Hearing Aids

Reference Reading: Hearing Aids and Bluetooth Technology

So, what is needed is a device, into which I place my phone and via a amplified speaker, I hear at a louder volume.
To reply with my caller I simply take up the phone and speak to them.

This method doesn't work very well, especially the part where you need to remove the phone from an acoustic coupled device to respond.

Or if it's a smartphone just put it on speaker. For most phones that's loud enough.